The spread of communication apparatuses has diversified the types of packets transmitted and received within a network and the lengths of data included in packets. In addition, packets each with a different priority have often been transmitted and received within the same network. When a plurality of packets each with a different priority are transmitted or received within a network, it is sometimes desirable to maintain a delay caused by a communication process performed for a packet with a high priority within a predetermined range. Accordingly, a technique has been proposed wherein, before a communication starts, a bandwidth to be used for the communication is reserved, and the communication is performed using the reserved bandwidth to prevent a processing delay from varying.
In a related art, a signal processing system is proposed wherein a guaranteed processing quantity is determined for each of the priorities of processing-object signals, which are processed in order of the priorities thereof and in the order of arrival under a condition in which the guaranteed processing quantities are upper limits, thereby enabling signals causing a large load and having a low priority to be processed. A node device has also been proposed that includes a plurality of transfer processing units and, in accordance with auxiliary information associated with information extracted from a received packet, selects a transfer processing unit for processing the received packet. The node device holds a processing management table that associates auxiliary information with the processing content of a received packet. The processing management table reflects the result of processing performed by a transfer processing unit and the load situation of the transfer processing unit. In addition, an apparatus has also been proposed wherein the amount of characteristic including features of reception data is extracted, a processing capacity required for a communication task is estimated using the amount of characteristic, and the processing capacity is adjusted using a difference between the estimated processing capacity and the processing capacity assigned to the communication task.
For example, Japanese Laid-open Patent Publication Nos. 1-209839, 2002-354009, and 2009-253520 are known.
Even in the case of performing a communication using a reserved bandwidth, when a software-based process is performed on a packet, such a process could cause a delay that is greater than a predicted delay. Hence, even when a communication band is reserved, depending on the processing capacity of a processing apparatus, it could have been difficult to maintain a delay time within a predetermined range.
Even in the case of using any of the methods described above as related arts, it is difficult to maintain a delay time within a predetermined range when the processing delay includes a delay caused by a software-based process performed on a packet.